Sulforaphane enhances progerin clearance in Hutchinson–Gilford progeria fibroblasts

Abstract

Hutchinson–Gilford progeria syndrome (HGPS, OMIM 176670) is a rare multisystem childhood premature aging disorder linked to mutations in the LMNA gene. The most common HGPS mutation is found at position G608G within exon 11 of the LMNA gene. This mutation results in the deletion of 50 amino acids at the carboxyl-terminal tail of prelamin A, and the truncated protein is called progerin. Progerin only undergoes a subset of the normal post-translational modifications and remains permanently farnesylated. Several attempts to rescue the normal cellular phenotype with farnesyltransferase inhibitors (FTIs) and other compounds have resulted in partial cellular recovery. Using proteomics, we report here that progerin induces changes in the composition of the HGPS nuclear proteome, including alterations to several components of the protein degradation pathways. Consequently, proteasome activity and autophagy are impaired in HGPS cells. To restore protein clearance in HGPS cells, we treated HGPS cultures with sulforaphane (SFN), an antioxidant derived from cruciferous vegetables. We determined that SFN stimulates proteasome activity and autophagy in normal and HGPS fibroblast cultures. Specifically, SFN enhances progerin clearance by autophagy and reverses the phenotypic changes that are the hallmarks of HGPS. Therefore, SFN is a promising therapeutic avenue for children with HGPS.

Temsirolimus Partially Rescues the Hutchinson-Gilford Progeria Cellular Phenotype

“…Additionally, in mock-treated cultures, most HGPS nuclei exhibited increased progerin accumulation at the nuclear envelope, with aggregates in certain areas as revealed when stained with anti-progerin antibodies (Fig 2D, upper panels). The HGPS nuclei that appeared normal showed reduced progerin staining [20]. Overall, both the number of bright progerin-positive nuclei and the signal intensity of these nuclei were reduced in temsirolimus-treated HGPS cells compared with mock-treated HGPS cells.…”

“…Mock-treated HGPS fibroblasts exhibited a significant increase in basal ROS levels (16.6%, p = 0.003) compared with normal cells (Fig 4G) [20]. Temsirolimus treatment of normal and HGPS cells resulted in no significant changes in ROS levels (Fig 4G).…”

“…Temsirolimus treatment of normal and HGPS cells resulted in no significant changes in ROS levels (Fig 4G). The basal levels of ATP in HGPS fibroblasts were significantly reduced (19.2%, p = 0.032) compared with mock-treated normal cells (Fig 4H) [20]. Temsirolimus treatment induced no changes in the ATP levels in either normal or HGPS fibroblasts (Fig 4H).…”

“…The results of the first clinical drug trial using an FTI (Ionarfarnib) are promising, as children demonstrated weight gain, improved bone structure, increased blood vessel flexibility [1], and slightly improved estimated lifespan [17]. Nevertheless, FTIs appear to induce disruption of the lamin B network, the formation of donut-shaped nuclei, and increased DNA double-strand breaks in HGPS cells [7, 18–20]. Therefore, the identification of new compounds that could promote the degradation of progerin will be of great interest for correcting the HGPS cellular phenotype.…”

Reactivation of latently infected HIV-1 viral reservoirs and correction of aberrant alternative splicing in the LMNA gene via AMPK activation: Common mechanism of action linking HIV-1 latency and Hutchinson–Gilford progeria syndrome

“…Indeed, p32 silencing significantly impaired both starvation-and rapamycin-induced autophagic flux [166]. Because AMPK has also been shown to regulate autophagy by phosphorylating and activating ULK1 and both rapamycin (mTOR inhibitor) and sulforaphane (isothiocyanate found in cruciferous vegetables) have each been shown to enhance autophagic clearance of progerin, a novel AMPK-p32 axis is further implicated, potentially decreasing progerin production via alternative splicing modulation while enhancing progerin clearance through autophagic induction [32,167,168]. Strikingly, Rivera-Torres et al showed that fibroblasts from HGPS patients exhibited a severe impairment in mitochondrial oxidative phosphorylation, characterized by markedly lower than normal expression of the mitochondria respiratory chain components cytochrome c, the complex V protein b-ATPase, and the complex IV component cytochrome c oxidase subunit I (COXI) compared to control fibroblasts [169].…”